The Proto-Australoids are a hypothesized group of ancient hunter-gather people descended from the first major wave of modern humans to leave sub-Saharan Africa ~100,000 years ago. This hypothesis of human migration was developed in the 1950s, but more recent scientific evidence suggests that the first surviving wave of modern humans to leave sub-Saharan Africa did so ~65,000 years ago rather than ~100,000 years ago.
Proto-Australoids are characterised by gracile body types, and are thought to have had deep dark-brown skin color and wavy, curly or frizzy black hair. They are also thought to have had long heads and broad, flat noses.
Furthermore, the most parsimonious hypothesis with regards to the physical appearance of the members of this group is that, similar to contemporary Africans, they expressed deep dark brown skin and black, tightly coiled, natural afro-hair (as opposed to the black, wavy or curly hair associated with Aboriginal Australians) (Windschuttle & Gillin, 2002). In light of the overwhelming evidence suggesting that the ancestral mammalian (including primate) hair texture was very likely within the range of straight/wavy to curly, the idea that the first modern humans expressed tightly coiled hair runs counter to the intuition that straight/wavy or curly hair was also the ancestral trait for modern humans.
Nevertheless, given the overwhelming evidence that humanity arose recently (~200,000 years ago) in sub-Saharan Africa, the extreme rarity of straight/wavy or even curly hair in contemporary sub-Saharan Africa in favor of tightly coiled Afro-hair suggests that, long before the development of our species (Homo sapiens sapiens), the ancestors of the first modern human migrants out of Africa had already adapted to conditions selecting for the unique sub-Saharan African afro-hair texture. In this sense, as suggested by Windschuttle and Gillin (2002), an intimation that the early modern humans resembled contemporary Aboriginal Australians is less parsimonious than the assertion that they more likely resembled contemporary sub-Saharan Africans (and/or "Negritos") in appearance.
Migration
The so called "proto-Australoids" (or, more likely, as suggested above, the "Afro-Negritos"), are thought to have begun their exodus out of Africa roughly 65,000 years ago. They are thought to have used a simple form of watercraft to cross the narrow span of water between the Red Sea and the Gulf of Aden.
From there it is hypothesized that they followed a coastal route through south Asia into Southeast Asia. While some individuals made an oceanic voyage into Australia (~50-60 thousand years ago), giving rise to the Afro-Negrito ancestral component of the Australian Aborigines (Windschuttle & Gillin, 2002), others continued their coastal migration north into East Asia.
The descendants of those who lingered near the Gulf of Aden eventually migrated northwards to populate Central Europe and adapted phenotypically to the new climate and latitude . Meanwhile, those descendants of the coastal migrants who continued their movement north into East Asia also adapted to a northern climate and latitude.
From there some believe that some of the Proto-Australoids pushed on into Siberia and eventually crossed the Bering Land Bridge (or followed a coastal route) into the Americas, contributing to a hypothetical population of Pre-Siberian American Aborigines, which some believe they have found evidence for in Brazil and in Tierra del Fuego.
The 1950s proponents of a "proto-Australoid" population wave theorize that remnants of this early founding population may be found today in the southern portion of the Indian subcontinent, Southeast Asia and Oceania. Some have proposed connections to the Ainu of Japan.
Genetically, they have been tentatively associated by some authors with mtDNA haplogroup M and Y-chromosome Haplogroup C-M130, the earliest Homo sapiens lineages thought to have migrated outside of Africa. However, while it is indeed true that the descendants of the first major wave of modern humans to leave sub-Saharan Africa migrated to all of these places and passed on these genetic patterns, it would be a misnomer to call such people "proto-Australoids" given that this evokes a phenotypic image that is not aligned with the most parsimonious explanation of the current evidence (Windschuttle & Gillin, 2002); indeed, these descendants evolved into Australoids (Archaic Caucasoids), who in turn evolved into Caucasoids.
In contrast to the above, other scholarship maintains that the term "Proto-Australoid" should be used, and the term "Afro-Negrito" should be abandoned. First, "Proto-Australoid" aptly describes genetically, and to some extent phenotypically, this people as those from whom the Australoids evolved. Second, the term "Afro-Negrito" is incorrect. These people are no more "Afro" than any other who have traveled out of Africa, and "Negrito" in particular is a racist 19th-century Spanish misnomer, an attempt to negrify a people who are not African/black/Negro at all, indeed, who are the most genetically distant from Africans, at most loci studied thus far (except for MC1R, which codes for dark skin). The Proto-Australoids's physical resemblance to Africans may result from random parallel mutations in different tropical environments. Proto-Australoids, however, also possess Asian and Caucasoid traits, and are accordingly classified as Asian/primitive Caucasoid.